Quick question: when an electron absorbs a photon with MORE THAN enough energy to jump one energy level but not two, what happens to the extra energy the electron doesn't absorb?
The probability, or cross sections for photon absorption for bond levels in atoms are extremely peaked at the frequency of the transition, [tex] h\nu = E_u - E_l [/tex], pretty much like delta functions. Well, they're actually Lorenzian profiles, but the width is extremely small, ~[tex]10^{-4} \AA [/tex] for most transitions. If the photon doesn't have essentially the same energy as the energy difference of the levels, it won't get absorbed.